教师在教学过程中处于组织者的地位，应充分发挥教师的__________作用。
参考答案：主导
—Who is suitable for the new chairperson of the Students’ Union?
—David is. He is ______ enough to come up with new ideas.
A．imaginative
B．humorous
C．modest
D．outgoing
下列物质中属于同分异构体的一组是（ ）
A．O2和O3
B．CH4和C2H6
C．CH3OCH3和CH3CH2OH
D．1H和2H
